Nearly half of all college students have a diagnosable mental health problem (Blanco et al., 2008). College counseling centers (CCCs) are faced with increasing demands for services from Universities, students and parents to meet the treatment needs of their students (Beamish, 2005), in the context of increasingly severe cases and declining resources (Gallagher, 2009). Innovative, cost effective solutions are needed that can improve treatment effectiveness with a range of presenting problems while reducing counselor workloads. The proposed project seeks to meet these needs by developing a web-based guided self-help version of Acceptance and Commitment Therapy (ACT;Hayes, Strosahl and Wilson, 1999), an evidence-based transdiagnostic therapy that has been found to effectively treat a range of mental health problems by targeting experiential avoidance, the tendency to avoid unwanted emotions and negative thoughts (Hayes et al., 2006). An ACT program would provide a means of implementing effective treatment for the range of problems encountered in the CCC setting, while the online guided self-help format would reduce counselors'workload for each client, improving cost- effectiveness and reducing waiting lists. This product would both treat students through a series of self-help modules and train CCC counselors in how to implement the guided self-help intervention. Phase I will focus on developing two self-help modules (mindfulness and acceptance) as well as a counselor portal to review students'use of the program and to receive training on implementing ACT guided self-help. Focus groups with treatment seeking students and focused interviews with counselors will be used to better adapt program content and design for these populations. The prototype self-help and counselor portals will be evaluated in terms of usability with think aloud procedures followed by a pre-post feasibility trial with 20 counselors and 60 clients (3 student clients per CCC counselor). Phase II will expand the program to include 12 self-help modules across the main ACT concepts: mindfulness, acceptance, defusion, noticing self, values, and committed action, with targeted content in the committed action module for specific problem areas based on initial assessment and counselor judgment. The counselor portal will be further developed to provide access to training material in relation to each module, to allow for greater interactions with and between students (e.g., addition of mobile technologies;creating a moderated forum for students) and to allow for advanced time-saving features (e.g., generating reports on student use of the program which can be filed as progress notes). These components together will provide a comprehensive self-help intervention for college students as well as a portal for counselors to monitor and support students'progress. The Phase II product will be evaluated in a randomized trial across various higher education settings, counselor expertise levels with ACT, and different program features. PUBLIC HEALTH RELEVANCE: College counseling centers are expected to serve an increasingly higher number of students, presenting with increasingly more severe problems, despite a concurrent reduction in or stagnation of available resources. The proposed project seeks to improve college counseling centers'ability to effectively and efficiently treat students presenting with a range of mental health problems, while reducing counselor workloads, by developing a web-based guided self- help program. A substantial percentage of the US population is in college at some point in their lives, and improving college counseling treatment programs could have a broad public health impact.